#!/usr/bin/node

const argv = process.argv,
      log  = console.log;
//validate argv
//argv number equal 3
if(argv.length !==3){
  log('cmd exit-code ');
  process.exit(1);
}
//code type is number
if(isNaN(Number(argv[2]))){
  log('argv must be number');
  process.exit(2);
}
//code range > 0
if(Number(argv[2]) < 0){
  log('argv must >= 0');
  process.exit(3);
}
//空值、数据类型、取值范围、模式

process.exit(argv[2]);
